The one on the steering arm looks like wear from a loose bolt. You can see material pushed up around the top of the hole. I can't see the point in slotting one side of a part that attaches to another at fixed points.

Tim, it's not a huge expense, but I don't consider the ARP rod bolts all that necessary for your projected usage. The early L16 bolts were small, but the later including the L20B I believe are 9mm and were considered in the "How To" books as sufficient for most HP usage. Your choice of cou...

Hello all, I have the following available immediately, for shipment or local pickup. L16 ITC spec shortblock $150 or offer L16 crankshafts (2), both cut 0.010" under $100 each 510 prop shaft stock length $75 510 rear axle shafts $50 for the pair Early 510 cylinder head (210?) core- have all par...